This event is one of the most perturbing in Scripture. Each time I begin to read of Jephthah, I dread what is coming. Why would he make such a strange vow, much less carry it out? Did he not understand the likely consequences of what he was promising? What was he thinking?
The Law includes the concept of redemption. In one sense, God provided the redemption of Isaac by providing the ram (Genesis 22:10-13). God redeemed Israel from Egypt. In Numbers 18:15-17, the LORD provides for the redemption of the first born of both man and animal; God even provides the redemption price. In light of all this, why could Jephthah's daughter not be redeemed? God explicitly declares in Jeremiah 32:35 He does not want children sacrificed: "They built the high places of Baal in the Valley of the Son of Hinnom, to offer up their sons and daughters to Molech, though I did not command them, nor did it enter my mind, that they should do this abomination, to cause Judah to sin."
To add to the perplexity of this event, Hebrews 11:32 commends Jephthah's faith: "And what more shall I say? For time would fail me to tell of Gideon, Barak, Samson, Jephthah, of David and Samuel and the prophets."
When I come to a part of Scripture, like the story of Jephthah and his daughter, that I cannot fathom, I always turn to Isaiah 55:8-9. "For my thoughts are not your thoughts, neither are your ways my ways, declares the LORD. For as the heavens are higher than the earth, so are my ways higher than your ways and my thoughts than your thoughts."
Lord God Almighty, forgive me for ever thinking of You like I would myself or other men. Your ways aren't like mine, and I am thankful they aren't. Thank You for redeeming me from a life more foolish than Jephthah's vow.
If you are curious about what Paul thought about those who taught "It is necessary to circumcise them and to order them to keep the law of Moses" read his letter to the Galatians. To peak your interest, I will give you a small sample.
In chapter one, Paul chastised the Galatians for leaving the Gospel and pursuing a false gospel. He says those who teach anything other than the Good News of Jesus are to be accursed even if it is an angel.
In chapter two, Paul clarifies the false gospel dealt with circumcision. He said false brothers wanted to rob them of their freedom in Christ Jesus and return them to slavery.
In chapter three, Paul asked if the believers in Galatia received the Holy Spirit through the law or through faith. Since they received the Holy Spirit by faith, why did they think they would be made perfect by circumcision of the flesh?
In chapter four, Paul reminds them they are not slaves but sons of God who cry "Abba! Father!" Since they are sons, why would they go back to what is useless? He pleads with them to live as he does—free from those laws.
In chapter five, Paul says everyone who accepts circumcision is obligated to keep all the law. In Christ Jesus, neither circumcision nor uncircumcision counts for anything, only faith working through love. He emphatically states "I wish those who unsettle you would emasculate themselves!"
In chapter six, Paul explains they want you to be circumcised so they can boast about it and claim you as their disciples.
Enjoy reading Galatians. Paul's opinion of those who add works to the Gospel is evident in this letter.
Acts 15:11 is a good summary: "We believe that we will be saved through the grace of the Lord Jesus, just as they will."
Abba! Father! Great is Your Grace. Brother Jesus, Great is Your Grace. Holy Spirit, Great is Your Grace.